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How To View vimtop Data in PerfMon

Vimtop is a valuable tool that can be used to ensure that your VMware vCenter Server Appliance (VCSA) remains as performant as possible. When it's coupled with a monitoring tool such as PerfMon, it's easy to spot trends or anomalies that are affecting your VCSA.

By Tom Fenton

08/24/2018

Used to monitor the overall health of and identify the processes that are running on and consuming your VMware vCenter Server Appliance (VCSA) resources, vimtop (as shown in Figure 1), is a real-time monitoring tool for VCSA. In a previous article, I showed you how to view vimtop data on a chart in an Excel spreadsheet, but you can view this same data by using Microsoft's built-in Performance Monitor tool, PerfMon, and in this article I'll show you how.

Capturing vimtop Data
Let's start off with a quick summary of how to capture vimtop data for historical analysis. The "-b" switch is used to start vimtop in "batch," which streams data to the console rather than displaying it on the console. Here's the command that I use to collect vimtop data every 60 seconds for 15 iterations and then redirect the data to a file called TOPMin.csv (the file should have a .csvextension if it's to be examined using PerfMon):

vimtop -b -c MemConfig -p 60 -n 15 > TOPMin.csv

By default, a lot of data is collected and emitted by vimtop, so I used a configuration file called MemConfig to limit this data flow. I would suggest that you read the articles I mentioned earlier to get a better understanding of how vimtop data can be captured by using the "-b" and "-c" switches.

The data output by vimtop consists of multiple lines of data. The first line contains the names of the counters for which the data is being collected, and each subsequent line denotes an iteration of the data collected. All the fields of data are contained in quotes and separated by commas. For example, if you specify "-n 15," you'll have 16 lines of data, the first being the name of counter and the rest being the data (Figure 2).

Transporting vimtop Data
Although PerfMon can read the output of the captured vimtop data directly so no other data transformation is required, you'll still need to transport the data once it's captured to a Windows system that's running PerfMon. Fortunately, modern versions of Windows desktop and server OSes have PerfMon preinstalled on them.

I found that using secure copy (SCP) to transport the data to a Windows system works well. In order to use SCP to transport data from the VCSA, however, you'll need to enable SSH and the BASH shell (which you should have already been done in order to access your VCSA and to run vimtop). Additionally, you'll need to set BASH as the default shell for your VCSA. To do this, log on to your VCSA as root and run the following command:

After you import the data into PerfMon, you'll be presented with a blank graph. To add counters to PerfMon, right-click in the graph area and select Properties (Figure 6), and then click Add; this will bring up a list of values that were captured (Figure 7).

Once the counters have been selected, click Add and then click OK. By default, it will display the data on a scale from 0 to 100. To change the scale, right-click in the graph area and select Properties, and then click Graph (Figure 8). If you select a counter that shows a percentage of resources being consumed, change the scale from 0 to 100 to 0 to 1. You can also change and customize other properties of the graph from this window, if you wish, such as the names of the axes.

Not only does PerfMon graph the data, it also displays the average, minimum, and maximum values and the duration of the information that you're viewing (Figure 9); this is one of the features I really like about PerfMon.

Another feature I find very helpful is the ability to select a specific region of the graph and then use the magnifying glass to zoom in to that segment of the graph (Figure 10).

[Click on image for larger view.]
Figure 10. Zooming in on a specific segment of the graph.

Wrapping Up
Vimtop is a valuable tool that can be used to ensure that your VCSA remains as performant as possible. When it's coupled with a monitoring tool such as PerfMon, it's easy to spot trends or anomalies that are affecting your VCSA, as well as in order to proactively address them and to ensure that your VCSA continues to perform at maximum efficiency.

About the Author

Tom Fenton works in VMware's Education department as a Senior Course Developer. He has a wealth of hands-on IT experience gained over the past 20 years in a variety of technologies, with the past 10 years focused on virtualization and storage. Before re-joining VMware, Tom was a Senior Validation Engineer with The Taneja Group, were he headed their Validation Service Lab and was instrumental in starting up its vSphere Virtual Volumes practice. He's on Twitter @vDoppler.